Severely disabled persons, particularly those confined to wheelchairs are prone to develop posture problems and deformities. If not corrected, improper or inadequate positioning can further exacerbate posture deformities. It has been estimated that 90% of persons who have been confined to wheelchairs, for two years or more, develop one or more posture deformities.
When a person's disability requires confinement to a wheelchair, various posture problems can result as a consequence of improper seating or positioning in the chair. For example, leaning to one side in a wheelchair can cause a condition known as pelvic obliquity, which results in one hip being lower than the other. If left uncorrected, pelvic obliquity often causes the person to develop scoliosis, an abnormal and severe curvature of the spine, and pressure sores. Slouching can lead to kyphosis, an abnormal backward curvature of the spine. Consequences of kyphosis include increased pressure on the coccyx and if carried to the extreme, a tendency to slip off the seat and possibly out of the chair. Further positioning or posture problems include abduction or adduction of the legs (the legs are either too far apart or too close together) and windswept hips (one hip is forward and the legs are swept to the opposite side), which can also lead to physical deformities. In children, these problems are particularly devastating because the deformity can become permanent within months if not corrected.
The prior art has attempted to alleviate positioning and posture problems with custom-designed wheelchairs which adjust to allow proper positioning of the legs, hips, torso, etc. and which are custom designed and built to alleviate the particular posturing difficulties of a specific patient. The advantage of this system is that it is immediately adjustable to the positioning needs of a specific patient and allows for body growth and other changes in the physical condition. However, this system is extremely cumbersome and expensive. Further, an individual's disability is accentuated by the increased equipment surrounding him. Finally, the increased equipment makes physical contact, such as hugging, difficult.
The prior art has attempted to alleviate the problems encountered with such custom-designed wheelchairs with custom molded seat cushions, such as the Pin Dot custom foam system. Custom molded cushions are designed and molded to meet the specific posturing needs of a particular patient. These attempts are successful to a limited extent. However, custom molding is a time consuming and expensive procedure and does not allow for on the spot correction of seating or posturing problems and is not flexible to a person's physical changing needs. Finally, in the case of a disabled child, a custom molded cushion does not allow for growth and in a few months time is obsolete for the particular physical needs of that child.
Problems with seat stability are also particularly critical with respect to wheelchair users. A cushion which provides for correct posture and thus stable seating enhances the users ability to wheel and turn the chair by grasping the wheels, to get in and out of the chair, to reach the floor to pick up an object and other types of movements. A cushion which lacks stability creates a fear of falling from the chair which will inhibit the user's range of movement. However, a seat cushion which provides a stable and comfortable seat and which assists in proving correct posture, will improve the user's equilibrium and sense of orientation.
The custom-designed cushions of the present invention overcome the foregoing problems as is more fully described below.